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Browser Extensions · head to head

Greasemonkey vs Logto

Greasemonkey logo

Greasemonkey

Browser Extensions

The original userscript manager, for Firefox

From
Free
Rated
-
Full reviewWebsite
Logto logo

Logto

Cybersecurity

Open-source identity and authentication infrastructure for apps and APIs

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: Greasemonkey firefox only. There is no Chrome, Edge or Safari build and there never has been.; Logto advanced features like RBAC, organizations, MFA, and enterprise SSO are billed as separate paid add-ons rather than included in Pro.
  • They diverge on capability: Greasemonkey covers Userscript execution, Logto covers Prebuilt sign-in UI.
  • Prices and features above were last checked on 17 September 2026.

Where they differ

Only the attributes on which Greasemonkey and Logto actually diverge.

Attributes where Greasemonkey and Logto differ
AttributeGreasemonkeyLogto
Pricing modelopen-sourcefreemium
PlatformsFirefoxweb, api
CategoryBrowser ExtensionsCybersecurity

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Greasemonkey

  • Userscript execution
  • Built-in script editor
  • GM. API
  • @resource support
  • Script localisation
  • Firefox for Android

Only in Logto

  • Prebuilt sign-in UI
  • Social connectors
  • Role-based access control
  • Multi-factor authentication
  • Machine-to-machine apps
  • Audit logs

What people use each for

The jobs each tool is most often brought in to do.

Greasemonkey

  • Restyling or de-cluttering a site you use dailynot Logto
  • Automating a repetitive action on a web applicationnot Logto
  • Adding a missing feature to a site you do not controlnot Logto
  • Running userscripts on Firefox for Androidnot Logto
  • Writing and testing your own scripts in the browsernot Logto

Logto

  • Adding sign-in to a new SaaS productnot Greasemonkey
  • Implementing SSO for B2B customersnot Greasemonkey
  • Securing internal APIs with M2M tokensnot Greasemonkey
  • Adding RBAC and organizations to a multi-tenant appnot Greasemonkey

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Greasemonkey

  • Firefox only. There is no Chrome, Edge or Safari build and there never has been.
  • Its API diverged from the Tampermonkey conventions most shared scripts are written against, so a script from a sharing site may need adjusting to run.
  • The dashboard is plainer than Tampermonkey's, with no diff view when a script updates itself.
  • No cloud sync of the kind Tampermonkey and Violentmonkey offer; moving machines means exporting.
  • A userscript manager can read and rewrite every page you visit, so the security of the arrangement depends entirely on the scripts you choose to install.

Logto

  • Advanced features like RBAC, organizations, MFA, and enterprise SSO are billed as separate paid add-ons rather than included in Pro.
  • Enterprise pricing is not published and requires contacting sales.
  • Token-based billing can make cost forecasting harder than flat per-MAU pricing for high-traffic apps.

Pricing, plan by plan

Greasemonkey

Free
  • Open sourceFree
    • Unlimited scripts
    • Built-in editor
    • No account required

Logto

Free
  • FreeFree
    • Up to 50,000 MAU
    • 50K tokens included
    • 3 applications
  • Pro$24/month
    • Unlimited MAU and applications
    • 3 included API resources
    • Passkey sign-in

Which should you pick?

Choose Greasemonkey if

  • You need userscript execution.
  • You want to start without paying.
  • You work on Firefox.
  • You also want built-in script editor.
Greasemonkey review

Choose Logto if

  • You need prebuilt sign-in ui.
  • You want to start without paying.
  • You work on web, api.
  • You also want social connectors.
Logto review

Questions people ask

Is Greasemonkey or Logto better?
Neither clearly leads. Greasemonkey starts at Free and Logto at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Greasemonkey or Logto?
Greasemonkey starts at Free and Logto at Free.
Does Greasemonkey or Logto run on more platforms?
Greasemonkey runs on Firefox. Logto runs on web, api.
Can I use Greasemonkey for free?
Both have a free tier, so you can try either at no cost before committing.
What is Greasemonkey best used for?
Greasemonkey is most often used for restyling or de-cluttering a site you use daily, automating a repetitive action on a web application, adding a missing feature to a site you do not control, running userscripts on firefox for android. Of those, restyling or de-cluttering a site you use daily and automating a repetitive action on a web application are not what Logto is typically brought in for.
What can Greasemonkey do that Logto cannot?
Greasemonkey covers Userscript execution, Built-in script editor, GM. API, @resource support. Logto covers Prebuilt sign-in UI, Social connectors, Role-based access control, Multi-factor authentication.

Answered from the vendors’ own pages

Greasemonkey: Is Greasemonkey still maintained?

Yes. Version 4.14 was released on 2 June 2026, and the project has an active repository, bug tracker and discussion groups.

Source
Logto: What does Logto cost?

Logto offers a Free plan at $0/month, a Pro plan starting at $24/month with 50K free tokens included, and a custom-priced Enterprise plan. Extra add-ons like RBAC or MFA are billed separately on Pro.

Source
Greasemonkey: Does Greasemonkey work on Chrome?

No. It is a Firefox extension and has never shipped for Chrome. Violentmonkey and Tampermonkey are the equivalents there.

Source
Logto: Is there a free plan, and what are its limits?

Yes. The Free plan supports up to 50,000 monthly active users, 3 total applications, 1 machine-to-machine app, 3 social connectors, 1 webhook, and 3-day audit log retention.

Source
Greasemonkey: Will Tampermonkey scripts run in Greasemonkey?

Often, but not always. Greasemonkey's API diverged from the conventions most shared scripts are written against, so a script may need its header or its GM calls adjusted.

Source
Logto: How is usage metered?

Logto uses token-based billing: only access tokens issued for authentication and authorization activity are counted, rather than charging purely per MAU.

Source
Greasemonkey: Does Greasemonkey run on mobile?

On Firefox for Android, from version 4.12. There is no iOS build, because Firefox on iOS cannot load extensions of this kind.

Source
Greasemonkey: What is the GM API?

The set of functions a userscript manager exposes to scripts, named after Greasemonkey, which defined it. Greasemonkey supports the promise-based GM. form including GM.xmlHttpRequest and GM.registerMenuCommand.

Source
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